The present invention is related to a spiral tube conveyor which can be used for moving any granular-type material from one location to another. More particularly, the present invention is directed to a spiral tube conveyor which can be either lengthened or shortened during its conveying operation.
Various types of conveyors for moving materials such as granular products, coal, ore, agricultural grains, farm silage, and the like, are well known in the art. The common conveyor comprises a screw mounted on a shaft which is rotatably disposed within a tube or cylindrical shell. In such devices, the material to be conveyed is introduced into one end of the conveyor and is conveyed to the other end of the conveyor by the rotation of the screw element disposed therein. However, in using the well known screw conveyor device, a number of problems have been encountered. For example, in the operation of the central screw element within the cylindrical shell of the conveyor, frequently the material being conveyed tends to collect between the peripheral edge of the screw element and the inside surface of the cylindrical shell, thereby adversely affecting the smooth rotation of the screw and, in some instances, causing a complete stoppage in the rotation of the screw element caused by the binding effect produced by said material. Also, if the material being conveyed contains a certain amount of moisture, it tends to compact between the convolutions of the screw element which again causes a binding effect within the screw element which can seriously affect the operation of the conveyor.
It has also been found that during a conveying operation it frequently would be desirable to either lengthen or shorten the conveying device in order to better accommodate the particular conveying operation. For example, in the mining of coal, as the mining operation proceeds, it would be desirable if the conveying device could be extended so as to follow the progress of the mining operation without the necessity of completely relocating the conveyor.
Accordingly, one of the objects of the present invention is to provide a spiral-type tube conveyor which eliminates all of the problems of the prior art as set forth hereinabove.
Another object of the present invention is to provide a spiral-type tube conveyor which eliminates binding problems between adjacent convolutions of the screw element or between the screw element and the cylindrical shell of the conveyor.
A further object of the present invention is to provide a spiral-type tube conveyor which can be lengthened or shortened at the site location, thereby readily adapting the conveyor to the mining progress made during the conveying operation.
Still another object of the present invention is to provide a spiral-type tube conveyor which is portable in nature and thus can be readily transferred from one location to another.
A still further object of the present invention is to provide a spiral-type tube conveyor which can effectively operate on an inclined plane while at the same time being capable of substantially increasing the conveying capability of the prior art devices.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the detailed description.
The spiral-type tube conveyor of the present invention comprises a cylindrical shell, containing a screw-type element, the periphery of said screw-type element being fixed to the inside circumferential surface of the cylindrical shell. When the screw element is affixed within the cylindrical shell, it defines a central aperture which extends along the entire length of the conveying device and which is generally coaxially disposed with respect to the cylindrical shell. The spiral-type tube conveyor of the present invention is rotated by associating a driving means with the outer circumferential surface of the cylindrical shell. Thus, in the conveyor of the present invention, both the cylindrical shell and the screw element attached thereto rotate in order to achieve the desired conveying operation. Because of the particular arrangement of the conveying device of the present invention, the use of an axis for mounting and driving the screw element is completely eliminated, thereby leaving a centrally disposed aperture through which large lumps of material and compacted material can be transferred during the conveying operation to avoid jamming of the conveying device and disrupting the entire conveying operation.
The screw element of the spiral-type tube conveyor of the present invention can be a separately manufactured element which is secured, e.g., welded, to the inside peripheral surface of the cylindrical shell or can be pressed out of the shell itself by any well-known manner. In any event, in its operational state, the screw element is integral with the peripheral inside surface of the cylindrical shell.
In one of the particularly advantageous features of the present invention, the spiral-type tube conveyor discussed above, i.e., the main conveyor, can be used together with at least one additional spiral-type tube conveyor in order to provide an overall conveying device which can be lengthened or shortened depending upon the particular needs of the situation. The additional conveyor comprises a cylindrical shell in which the screw element is pressed out of the cylindrical shell itself. To help understand this particular structure, one should visualize a cylindrical tube which contains a spiral line drawn on the outer surface of the tube. Then, if one were to press on said spiral line inwardly toward the center of the tube, the result would be a substantially U-shaped groove which extends toward the center of the tube and extends along the peripheral surface of said tube with a spiral configuration. If the U-shaped groove is pressed from the tube itself, it will be apparent that in order to conform the diameter of this conveyor to the main conveyor discussed hereinabove, the diameter of the tube before the pressing operation must be much larger in order to provide enough tube to accommodate the grooves which are to be pressed therein. In order for the two conveyors to be combined into a single conveyor which can be lengthened or shortened, the additional conveyor of the present invention must have a shell diameter which is slightly smaller than that of the main conveyor discussed above so that it can be readily screwed into said main conveyor. Thus, the additional conveyor which contains the U-shaped pressed-in screw can be readily screwed into the main conveyor because the screw of the main conveyor, which is attached to the inside peripheral wall of the cylindrical shell, is received into the pressed-in, U-shaped screw of said additional conveyor. Since the U-shaped screw is pressed toward the center of the tube a distance at least slightly greater than the distance the screw of the main conveyor extends toward the center of the main conveyor, the additional screw element forms a female receptacle which receives the male screw element of the main conveyor. As can be readily visualized, an additional screw element can be screwed into both ends of the main conveyor, thus making it possible to increase the length of the spiral-tube conveyor by almost 100%. It can be readily realized that although the present invention advantageously utilizes a combination of screw elements to produce a conveyor which can be varied in its length, any of the elements mentioned above, that is the main conveyor or the additional conveyors, can be utilized independent of the other conveyors to produce an effective conveying device.
When the various conveyors are utilized in combination, the main conveyor can be disposed as a central unit with the additional conveyors being adapted to be screwed into both ends of said main conveyor. Various well-known, hydraulic means can be utilized for moving the various conveyors relative to each other, i.e., for screwing the additional conveyors into the main conveyor. Also, belt conveyors can be associated with either ends of the spiral-type conveyor of the present invention to facilitate loading and unloading of the conveyor.